HELP! "Keyboard is locked out - Unlock the key"

Ok, this is a really weird problem. I just installed a new hard drive on my
Asus A7V266-E mobo and now when I boot up, I get the message "Keyboard is
locked out - Unlock the key" after the POST. Here's the strange part, when
I lay my PC on its side, I don't get the message and the PC boots up fine.
While the PC is running, if I stand it up again the keyboard stops working!
What the heck is going on? There were some forums I found on Google that
suggested it could be a problem with grounding but there doesn't seem to be
anything moving when I move my PC around. Can anyone help me out?

Thanks,
Mitchua